According to Democratic pollster Jim Gerstein, few voters place Israel as high on their list of issues as Gallagher. Citing Gallup and Pew polls, Gerstein said that Israel didn’t rank in the top 10 of issues voters considered on Election Day – even among Jewish voters. He argued that all signs pointed to a Jewish American voting base that was strongly entrenched in the Democratic Party.

“Even with the slight lessening of support for Obama, and we are talking about a couple of points, I don’t see it making a real difference,” said Gerstein.

Obama, meanwhile, also has campaigned heavily for the Jewish vote.

On Friday morning, Obama with considerable fanfare was photographed in the Oval Office signing the United States-Israel Enhanced Security Cooperation Act. The law gives Israel $70 million in military support and significantly expands cooperation between the U.S. and Israeli militaries. Just days before Romney’s visit, it successfully stole headlines in Israel away from the Republican’s planned trip and fundraiser.

The White House rejected suggestions that the signing – the day before Romney arrives in Israel – was politically motivated. Press Secretary Jay Carney said Congress passed the bill earlier this month and sent it to Obama for signing last week. His first opportunity to sign the measure was Friday, Carney said, as he’d been out of town all week.

"The timing of the passage and the signing of this legislation was not up to us, but up to Congress," Carney said. "I understand the coincidence. But the fact is our cooperation with Israel on its security is a subject we could discuss every day."

Lesley Clark of the Washington Bureau contributed from Washington.